1. Field of the Invention
This invention relates to preventing cross-contamination when using a dental scaler device, and more particularly to sterilizing a dental scaler handpiece.
2. Description of the Prior Art
Dental scaler devices are known in the art for cleaning teeth. Generally, dental scaler devices vibrate a scaling tool at ultrasonic frequencies to facilitate the removal of calculus from a patient's teeth. Ultrasonic dental scalers usually comprise a handpiece adapted for receiving a dental scaler insert which includes a scaling tool, a flexible cable connecting the handpiece to a housing and the dental scaler device electronics contained within the housing. There are several different types of ultrasonic dental scaler devices including magnetostrictive scaling inserts and piezoelectric scaling inserts. For vibrating a magnetostrictive scaling insert, the handpiece generally includes an energizing coil which is positioned to surround a transducer of a magnetostrictivedental scaler insert placed within the handpiece of the scaler device. The magnetostrictive scaler insert generally comprises a transducer formed from a stack of laminar plates of magnetostrictive material that is excited by the energizing coil to longitudinally expand and contract at an ultrasonic frequency, such as about 25 kHz.
During the scaling procedure using conventional ultrasonic dental scaler devices, a patient's gums tend to bleed to some degree. Thus, when using dental tools such as a dental scaler, it is necessary to present to the patient a sterile surface. It is important that sterilized tools be used because bleeding will most likely occur during the scaling procedure, which presents a danger of transmission of Hepatitis-B and HIV, for example, if a contaminated dental scaler device is used. In the case of a dental scaler device, not only does the scaler insert require sterilization, but the handpiece of the device should also be sterilized since blood and saliva from a patient can easily come in contact with the handpiece.
Presently, scaler inserts are sterilizable by steam autoclaving which has been proven effective in preventing the transmission of Hepatitis-B and HIV. However, the handpiece of the conventional dental scalers are not designed to be autoclaved. Thus, the handpiece exterior surface is commonly cleaned by wiping the handpiece with a chemical sterilant. Simply wiping the exterior surface of the handpiece with a chemical sterilant is not considered to be acceptable practice for the prevention of the transmission of Hepatitis-B and HIV.
Other methods of sterilization such as ultra-violet (U.V.) irradiation are also available for sterilizing equipment such as dental scaler devices. U.V. irradiation has the disadvantage of taking a prolonged period of time to completely sterilize the equipment, thereby not allowing that particular piece of equipment to be readily reused with another patient. U.V. sterilization also has the disadvantage of not providing complete sterilization but only sterilizes those surfaces exposed to the U.V. irradiation. A common solution to this problem is the acquisition of numerous pieces of the same type of equipment, thereby allowing use of one instrument while others are being sterilized. For example, it is quite common for a dentist to have numerous dental mirrors and dental picks of the same type to be used while others are being sterilized. However, when the equipment requiring sterilization is an expensive, complex device, it is unlikely that a dentist will have more than one dental scaling unit. Thus, it is impractical to always sterilize a dental scaler handpiece.
Presently, dental scaler handpieces cannot be effectively and efficiently sterilized to prevent cross-contamination among patients.